The reformulated Koiter–Newton method for thermal–mechanical buckling and postbuckling analysis of thin‐walled structures

Abstract

The reduced-order modeling method, termed as the Koiter-Newton method, is reformulated to be applicable for geometrically nonlinear thermal-mechanical analysis of thin-walled structures. The thermal load is treated as the independently unchanged load corresponding to the initial temperature field. The internal force space is expanded using the mechanical load, the thermal load, and the predefined perturbation loads. The thermal-mechanical reduced-order model is constructed using the first to fourth-order derivatives of strain energy with thermal effects in terms of the degrees of freedom (DOFs). An additional DOF related to the thermal load appears in the construction of reduced-order model based on the novel Koiter theory. The path-following scheme is proposed to make the method able to trace the entire geometrically nonlinear thermoelastic response.A much larger step size can be achieved benefiting from the favorable prediction of the reduced-order model, compared to the classical Newton-like methods. Both the temperature-independent and temperature-dependent material properties are considered. The thermal-mechanical buckling and postbuckling behaviors obtained by the proposed method are validated and discussed using various numerical examples.

Thermal-Mechanical Buckling and Postbuckling Analysis of Thin-Walled Structures Using a Reduced Order Method

“…A much larger step size can be achieved benefiting from the favorable prediction of the reduced-order model, compared to the classical Newton-like methods. Various numerical results have been used to validate the excellent performance of the proposed method in thermal-mechanical buckling analysis [1,2].…”